find /media/cdrom/ -name '*27918*' | xargs -i cp {} ~/Desktop/

This then copies anything with 27918 in the title to your desktop, which is much quicker than searching through every file on the cdrom for example.

The only difficulty is making sure you know which page numbers you need, there is often a mismatch between the page number shown and the ones you need as the contents page often isn’t counted.

When I was offered my permanent position, my boss at the time congratulated me on my new position and gave me two pieces of advice: Firstly: do not be afraid to share your passion for your subject!  Secondly: do not be surprised if no-one in the audience shares your enthusiasm.  This is something which I’ve tried to stick to, though my enthusiasm for finite differencing schemes is somewhat limited…..

In no particular order some other tips:

• Do not over prepare.  After the first few lectures your style will change so avoid trying to have the whole course ready from the start.
• When preparing remember that learning is all about getting the students to do things, so use some sort of active learning.  Richard Felder has some excellent web pages about how to do this.
• Students are really only interested in what is in the exam.  This is in some ways a bit shallow but I have a lot of sympathy with this viewpoint – if what you are trying to get them to do is not rewarded by marks then there is something wrong with your course!  So make sure that what you want them to do and what you assess are the same thing.
• Be a bit of a bastard!  When I started out we were on an educational journey together and when people talked I would meekly ask them if they could possibly pay attention.  Chatting during the lecture did actually disrupt the learning and it would be better for all of us if they could save their conversation till later -  if it wasn’t too much trouble for them that is.  I’m now much more robust with them and this works a lot better, though I am astonished about how many of my colleagues put up with background chatter.
• Always welcome contributions from students.  It is much better to have some contributions (even if they are wrong) than have no-one engaging with your lecture.
• Use technology but remember the key thing is to get students doing things.  So whilst it is nice to have colour pictures, or films in your lecture – getting students to actually do the problem sheets is much more useful.
• Watch other staff lecture and copy elements of their style that you think will work.  You can also read general advice on-line, though bear in mind that this all gets a bit generic as it has to cover a huge range of subjects.  It is much better to watch the good lecturers at your University in your subject.

I’ll try and do another post in the future about how I suggest that you ensure that people pay attention and some ideas of encouraging interaction.

This post will be of interest to you if you are running a linux box and trying to share pictures (and music and videos) around a local network using the DLNA system/protocols.

If you want to access photographs from a PS3 from a server you can do the following:

1. Install mediatomb I used the version available in the standard Ubuntu repository.
2. Set up a dedicated mediatomb user, I called this user dlna but you can of course use anything.
3. I then symlinked using ln -s the directory where I put the photographs (for now) that I want to share around my home network to a file in the dlna user’s home directory.  So the full command was something like: ln -s /media/DLNA/ DLNA
4. Run mediatomb from the command line and then edit the config.xml file that this creates in the dlna user’s home directory.  I turned off the UI as even though my network is protected by a password I didn’t want to make the file system read write to everyone.  I also un-commented the appropriate part to allow PS3 support.
5. Run mediatomb -add /home/dlna/DLNA note that you need to use the full path to get the files to be added.

This all seems to work just fine.  All I need to do now is to get mediatomb to start up on the machine startup and secondly check that anything I drop into /media/DLNA gets picked up and shared around the home network.

I recently had the privilege of travelling from Newcastle Airport in the UK all the way to Vancouver to attend the ASME Turbo Expo.  It is amazing to me that you can get from one side of the world to the other in a mere nine and one half hours, travel at over five hundred miles an hour, in air that is too cold and too thin to breath, over inhospitable terrain, around treacherous weather and the thing that most concerns people is what is on the telly.

I appreciate that leaving the seat back TVs do not have enough contrast to be seen clearly if the shades are open, but you are missing on some wonderful views and it is a bit of shame that the flight attendants come around and ask for the window shades to be closed.

Now I know I’m something of an aviation geek – I do turbines for a living after all – but I’d like to see much more on the moving map than just the altitude and the ground speed.  There really ought to be a mode where you can see most of the key flight information: yaw, pitch, various airspeeds, rate of climb and a nice high definition camera looking out the front, back and sides of the plane.  Until then I will just have to annoy people by walking up to the emergency exit door and pulling the window shade up…

Incidentally Air Canada gets the thumbs up: reasonable legroom, comfortable seat, nice TV and o.k. food.  Personally I like a chatty flight crew but the ones on the way back were a bit quiet but perhaps being an overnight flight they wanted to let people sleep…  Speaking of Air Canada I’ve been enjoying the blog of Captain Doug Morris, you should too.

1. Students tend to think of problems as a series of special cases and don’t do a good job of connecting the underlying engineering theory.
2. The steady flow energy equation is an awesome piece of underlying theory.

The steady flow energy equation (SFEE for short) for those who don’t recall is an energy of analysis of systems with a number of flows in and out of them.  It relates work and heat  transfers across the boundaries to enthalpy changes, velocity changes and gravitational potential energy changes.  I would put this into an equation but frankly the in-built editor for this blog doesn’t handle equations very well.

Anyway with the SFEE allows you to analyse:

• open and closed feedheaters
• gas mixtures
• cooling with and without condensation, heating with and without evaporation
• humidification by spraying
• turbines, expanders, pumps and compressors

Basically it is one of only a handful for key pieces of knowledge you need for an undergraduate education in engineering thermodynamics – the rest is application.

This is something I will be emphasising in future courses…

Moving through history I am no setting up a “snowcam” so that I can view the snow at my house over the web.  1999 is calling and would like its technology back!

So there are a number of tools I am using to get this done:

• fswebcam which is a very simple program for getting an image out of the camera aka “fswebcam –resolution 1280×800 webcam.jpg”
• expect to run an automated script to upload to a webdav server
• cadaver to actually put the files on the web server
• cron to automate the job.  In theory this will upload a picture of my car everyone morning at 8:10am!

So we shall see if this actually works!  If it does I’ll put the scripts up – it has been a lot more complicated than I thought it would be.

Edit: o.k. for some reason this doesn’t work at all.  I blame the cron job – I’ll update if I get it working…

Edit2: professional tip, to get cron to run point it at something that is actually executable…  this should now work!

In a fit of enthusiasm I decided to try and get three papers into the conference and thanks to the efforts of my co-authors have largely succeeded.  It was an enormous amount of work and I’m not sure I want to go through that again!  Anyway we ended up with three papers in the final programme:

• THE EFFECTS OF IMPROVED STARTING CAPABILITY ON ENERGY YIELD FOR SMALL HAWTS (GT2011-45674)
• TIME RESOLVED MEASUREMENTS IN THE DURHAM CASCADE (GT2011-45838)
• PROFILED ENDWALL DESIGN USING GENETIC ALGORITHMS WITH DIFFERENT OBJECTIVE FUNCTIONS (GT2011-45836)

The second two refer to detailed measurements conducted inside the cascade and a design system to improve the performance of turbine blades using profiled endwalls.  These cover slightly more complicated concepts than the first one and I’ll see if I can get around to doing individual posts on each of them in turn – but no promises!

Anyway the first paper is about Horizontal Axis Wind Turbines or HAWTs for short.  (Normally I detest abbreviations but I seem to have one in a title there – oops)  This paper basically looks at how important starting performance is on the overall energy yield of a small wind turbine and according to our calculations it is quite important.

The paper is mainly based on a model of turbine start-up developed by Supakit using the MATLAB-SIMULINK modelling environment, we validated the model against some data kindly provided by  Professor David Wood at the University of Newcastle, Australia so we have some idea that the model produces outputs that are reasonable.  Essential the model uses a simple blade element momentum model of the wind turbine blade and a model of the various load types that the wind turbine might be connected with and enables us to calculate the energy yield under various wind conditions.

The picture below shows a figure from the paper showing how the revised blade designs (MX and MP) compare in terms of rotational speed to the original design (SG).

Start Up Curve for Original and Revised Designs

The headline result is that designing your wind turbine to start up more quickly can increase your energy yield by up to 40%.  However it can also reduce your energy yield under certain load types by around 4% so careful attention to the design is necessary.  One key message from the paper is that understanding more about the physics of the flow around the wind turbine at startup is a useful thing to do.

You will doubtless have struggled as I have with ensuring that your nomenclature section is up-to-date and comprehensive.  Normally this involves printing out the document and ticking off the symbols in the nomenclature as you go through the document symbol by symbol.  The sort of dreary drudgery that computers should take care of.  A short web search reveals that they do.

The nomecl package provides a good solution.  Essentially you add nomenclature information into the document where you first use the symbol and it then compiles it into a nomenclature section.  There are a couple of things to watch out for though.

Your latex document needs to have \usepackage{nomencl} in the preamble and a \makenomenclature where the \maketitle command usually goes (well this worked for me anyway) you need to put \printnomenclature where you would like the nomenclature section to appear.

After you first use the symbol you want in the nomenclature commands such as: \nomenclature{$C_{P0}$}{Loss coefficient}% are required. Note the trailing % sign.

In order to actually get a nomenclature you need to run makeindex (thanks for this tip from Ulrike Fischer):

# pdflatex draftreport
# makeindex draftreport.nlo -s nomencl.ist -o draftreport.nls

Did the job for me. Further details are of course in the fine manual which you should probably read…..

Despite this most professional engineers use them as often as they would use a bit of paper, but I’ll get back to why they are evil:

• There is no logical flow to the calculations – it is like following a program with huge numbers of goto statements – like trying to follow directions on a tube map of London with a teleport function
• The variable names aren’t meaningful A23 is pressure, where is B23 is velocity
• The data and the manipulation logic are intimately linked.  If you want to repeat the operation on another set of data you need to copy and paste and if you have more data points then you have to make sure all the cell limits match up.

All this means that spreadsheets are extremely error prone.  For example the one I used today put together by one of the sharpest tools in the box had one serious systematic error in it and one quite minor one.  Errors arise in programming environments too but then you can change the code and run it on the data again – fixing it in the spreadsheet was time consuming as I had to go through each set of data and correct the analysis error in each sheet.

Despite this they are extremely popular amongst my fellow engineers because they allow you to immediately adjust, alter and plot data.  Although better alternatives exist that have much more sophisticated possibilities such as: GNU Octave or SciPy I guess almost any computer has a spreadsheet on it.  When I worked for a prominent North of Scotland power generating company back in the day analysis was largely done in spreadsheets as installing software had a large overhead associated with it.  There was some massive spreadsheet that worked out the efficiency of the power station but no-one knew how it worked and I spent a few weeks implementing a pipe-flow analysis program in Lotus 1-2-3 – all of which would have been much easier with an actual programming language.

However I have learned the error of my ways – spreadsheets are evil – avoid them!